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This study was carried out with the aim of comparing the phenotypic variations of growth and reproductive performances among seven heritage varieties of turkeys with hybrid turkeys. Differences among turkey varieties for Body Weight (BW), Average Daily Gain (ADG) and Feed Conversion Ratio (FCR) were significant (p≤0.05) with Narragansett being the heaviest and Royal Palm showed the lowest BW and ADG. The mean ADG gradually increased up to 159 days of age and then decreased thereafter in heritage turkeys. Consistently better FCR for males and females reported in Blue Slate and White Holland, respectively. Narragansett was characterized by the highest semen volume and sperm count, while Bourbon Red had the lowest. White Holland had the highest sperm concentration and viability, while Bourbon Red had the lowest. Age at first egg (AFE) was also different among turkey varieties. Heritage turkeys are generally characterized by late sexual maturity. Among heritage varieties, Midget White reported the least AFE and highest egg productions than others. As expected, hybrid turkeys were superior to heritage birds in performance for most of the traits evaluated in the study. In conclusion, the differences observed in growth and reproductive performances within heritage turkeys could be useful for future breeding programs to improve the existing production and reproductive performances of turkeys.

Objective: The aim of this study was to screen the chLEAP-2 gene for DNA sequence variation and to evaluate the relationships among its haplotypes (based on haplogroups), expression levels, weight gain and lesion score in two chicken lines challenged with Eimeria maxima. Methodology: A total DNA sequence of 4.6 kb including the chLEAP-2 gene was screened by re-sequencing of individual amplicons. Sixteen SNPs, including seven each in the promoter and introns and two in exons, were identified. Results: One of the exonic single-nucleotide polymorphism (SNPs) was non-synonymous, involving a cysteine to tyrosine codon change. About 25% of the SNPs were in Hardy Weinberg equilibrium. Linkage disequilibrium (D) among the SNPs ranged from 0.02-1.00. The haplotypes observed from the 16 SNPs were assembled into 5 haplogroups. The estimated frequencies of the haplogroups ranged from 0.17-0.23 in the combined chicken lines. Although not significant (p>0.05), the chLEAP-2 gene expression varied among haplogroups. Differences among haplogroups for lesion score and weight gain were consistent, but not statistically significant (p>0.05). However, Hap4 appeared to be the haplogroup least susceptible to coccidiosis. At a minimum, the data do not support an association between chLEAP-2 DNA sequence variation and symptoms of coccidiosis such as weight gain depression and lesion score. Conclusion: Therefore, earlier reports of differences between resistant and susceptible lines in chLEAP-2 expression may be due to trans-acting factors. The genomic results reported here provide resources for testing the trans-expression control theory and will be useful for future genotype:phenotype evaluation studies between chLEAP-2 and other traits in the chicken.

Background and Objective: Biological clock controls behavioral, physiological and biochemical circadian rhythms of animals. Circadian clock genes including period3 are involved in the circadian clock mechanism. The present study was conducted to test the hypothesis that differences in DNA sequence variations of the turkey period3 (turPer3) gene may be associated with performance traits including growth and reproduction. Methodology: The turPer3 gene was screened for DNA sequence variations and evaluated the relationships among haplogroups with performance traits. The DNA sequences of turPer3 (16.6 kb) gene were screened using 290 turkey birds by re-sequencing the individual amplicons. Results: Seven SNPs, including one each in exon 18 and intron 5, two SNPs in exon 19 and three SNPs in intron 6, were detected. The SNPs detected in the exon 19 were non-synonymous, which changed the amino acids from methionine to threonine and serine to phenylalanine at 953rd and 955th positions, respectively. Linkage disequilibrium (D) among SNPs ranged from 0.03-1.00. Pairwise FST ranged from 0.01-0.43. Haplogroup frequencies of the turPer3 ranged from 0.02-1.00, were significantly associated with body weight (BW) at 231 days of age, average daily gain (ADG) for the period of 160-231 d of age, FCR for the periods of 69-159 d and 160-231 d, egg production and semen quality traits (p≤0.05). Conclusion: The DNA sequence variations of turPer3 gene are significantly associated with BW, ADG, FCR, egg production, egg weight and semen quality traits. turPer3 gene may seem to have some regulatory role in the molecular mechanism of the circadian clock. Genomic reagents reported in the present study would be valuable for future genotype: phenotype evaluation studies in the turkey using a candidate gene approach.

Background and Objective: A study was conducted to test the hypothesis that differences in DNA sequence variations of turkey Clock gene may be associated with growth and reproductive traits. The turClock gene for DNA sequence variations was screened and evaluated the relationships among its haplotypes (based on haplogroups) with growth and reproductive traits of the turkey. Methodology: A total of 290 birds including hybrid turkeys and seven different varieties of heritage turkeys were used. DNA sequences of turClock gene (24.6 kb)were screened by re-sequencing of individual amplicons. Haplogroups were determined based on the output from Visual Haplotypes and data were analyzed to find out the associations between genotype and phenotypic traits. Results: Twelve SNPs, including five, four and three in introns 6, 9 and 16 respectively, were identified in the turClock gene. Reported SNPs were not in the Hardy-Weinberg Equilibrium (HWE) (p≤0.05). Linkage disequilibrium (D‘) among SNPs ranged from 0.05-1.00. Pairwise fixation index (FST) ranged from 0.03-0.90. Five haplogroups were developed from 12 SNPs. Haplogroups frequencies ranged from 0.03-0.93, were significantly associated with body weight (BW) at 309 days of age, feed conversion ratio (FCR) for the periods of 34-68 and 69-159 days, egg production and average egg weight (p≤0.05). Conclusion: The haplogroups of the turClock gene are associated with growth and reproductive traits. DNA sequence variations of Clock genes at the nucleotide and haplotype levels are associated with differences in performance traits. The genomic information described in the present study would be valuable for future association studies between Clock gene and other economically important traits in the turkey using a candidate gene approach.